The present invention relates to a process for manufacturing a ceramic part, for example a brick, plate, rod or pipe, to be used in a high temperature environment or application and that is preheated prior to such use, such process including forming the refractory part by shaping and subjecting such part to a heat treatment operation, to thus impart to the part properties suitable for the high temperature use. The present invention particularly is directed to a process for the manufacture of such ceramic parts that are employable in metallurgical continuous casting insulations.
According to the state of the art, such ceramic parts are shaped of a ceramic mixture of suitable materials and then are subjected to a heat treatment operation, particularly a firing operation. After such heat treatment operation the parts then are cooled down and stored, and subsequently are assembled on location at particular positions of use according to their respective intended purposes. Prior to utilization at such positions of use, and particularly in high temperature environments, it is necessary that such parts be preheated. Such preheating is necessary for a number of reasons, and particularly is desirable in metallurgical continuous casting installations.
U.S. Pat. No. 3,435,992 discloses a shaped ceramic part employed as a funnel for a nozzle of a metallurgical vessel in a continuous casting installation. The nozzle is heated on location electrically. If the nozzle is electrically conductive, heating is achieved inductively by an induction coil. Capacitive or dielectric heating and resistance heating also are possible.
U.S. Pat. No. 4,359,625 discloses a shaped part in the form of an immersion nozzle for a continuous casting installation. The immersion nozzle is heated by resistance heating on location at the position of utilization, and the material of the immersion nozzle is electrically conductive. Heat installation is proposed to reduce heat dissipation of the heated immersion nozzle.
German patent application P 40 35 496.2 discloses a device wherein an immersion nozzle is swiveled by a heating device into position in a continuous casting installation.
In all such known prior art systems, the shaped ceramic part first is formed, for example by molding or another shaping operation, and subsequently is heat treated, for example fired. This completely finished shaped ceramic part then is moved, with possible intermediate transportation and storage, to a position of utilization whereat it again is necessary to preheat the part before it can be used in the particular high temperature environment. This procedure of manufacture involves a substantial expense, and particularly a substantial consumption of energy. Thus, substantial energy is required both for the heat treatment operation during manufacture of the ceramic part and then later for the preheating of the part at the position of utilization.